I live on the rea sea coast of Egypt (Hurghada), and I really want my parents to use solar power. How big or how many panels do we need. Our house uses around 1000 KiloWatts per/month

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Answer by Siemens vs. Alstom
1000 kWh/month / 270 hours of sunshine/month (November, minimum amount of sunshine)=
3.7 kW power needed to be collected/sunshine hour. However, remember that solar panels are not 100% efficient and there are clouds a lot of the time -> 4.2kW I would suggest if you want to be completely self sufficient. However it is unlikely that you always use exactly 1000 kWh/month, probably in the summer it’s more for A/C and winter it’s more for heating (although looking at avg. temperature in your city makes me think heating is not really important).

However, if we assume that you use the most power in July (warmest month according to Wikipedia + most sunshine hours) then 1000kWh/month / 403 hours of sunshine/July = 2.5 kW power needed to be collected/sunshine hour. Giving the buffer space for inefficiency, 3 kW set up should be sufficient. In the darker months you may have to draw electricity from the grid. If you are planning on connecting to the grid to offset your power bill, that’s no problem. If you’re planning on going completely off grid, you will need batteries and a generator for the darker days.

However, I would suggest lowering your power consumption, as that is cheaper than installing extra generating capacity. Use some fans instead of A/C. A fan uses no more energy than a light bulb (80 watts) whereas an A/C system usually goes in the 1000s of watts usually around 1.5 kW. That could probably be half of your energy usage. Also if you are using a hot water heater, try to make a simple solar hot water heater, which is much cheaper than PV panels and saves energy.

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